                a) Field of the Invention        
The present invention relates to an audio system, a control method thereof, and a recording media on which a program of the method is recorded, and in particular, to an audio system capable of changing an acoustic effect or a sound effect using a graphical user interface (GUI) and a digital signal processor (DSP), a control method of the audio system, and a recording media on which a program of the method is recorded.                b) Description of the Related Art        
FIG. 13 shows a block diagram an outline of an amplifier system as an example of a stand-alone audio system of the prior art.
An external compact disk (CD) player supplies a digital audio signal or an analog audio signal to a CD player terminal T1. An external tuner inputs an analog audio signal to a tuner terminal T2. Other audio signals are fed to a first auxiliary terminal T3 and a second auxiliary terminal T4. An input selector SL is connected to the terminals T1 to T4. The selector SL includes a digital-to-analog (D/A) converter and an analog-to-digital (A/D) converter, which are not shown. An analog audio signal is delivered via the selector SL to an audio amplifier section AM. The amplifier section AM conducts a digital signal processing (DSP) for the received signal, amplifies the resultant audio signal, and then outputs the amplified signal to a speaker terminal Ts. The terminal Ts is connected to a loudspeaker, not shown. A central processing unit (CPU) 150 controls the overall operation of the amplifier system AS. A read-only memory (ROM) 151 stores various programs for DSP, data for DSP, various control programs, and control data. A random access memory (RAM) 152 serves as a work area to temporarily store various data items. A display section 153 displays various information items such as a sound source being selected and a DSP mode. An operator panel 154 includes various types of operation keys.
A bus 155 connects the input selector SL, the CPU 150, the ROM 151, the RAM 152, the display 153, and the operator panel 154 to each other.
Operation of the amplifier system will be briefly described.
First, description will be given of a situation in which DSP is not conducted. When a user activates a selection switch, not shown, of the operator panel 154, an operation state of the panel 154 is notified via the bus 155 to the CPU 150. The input selector SL connects under control of the CPU 150 one of the terminals T1 to T4 to the audio amplifier section AM.
An external equipment inputs an analog audio signal or a digital audio signal via the selector SL to the amplifier section AM. The amplifier section AM amplifies the input signal and then outputs the amplified signal to the speaker terminal Ts. The speaker connected to the terminal Ts sounds.
Concurrently, the display section 153 displays information of the selected sound source (e.g., a CD player) or the like.
Next, description will be given of a situation to conduct DSP. When a user operates a selection switch and a DSP mode selection switch, not shown, of the panel 154, an operation state of the panel 154 is notified via the bus 155 to the CPU 150. Under control of the CPU 150, the input selector SL sequentially stores a digital signal obtained by converting an analog audio signal inputted from one of the terminals T1 to T4 or a digital audio signal therefrom in an RAM for DSP, not shown, in the audio amplifier section AM.
The CPU 150 operates as a digital signal processor. Specifically, the CPU 150 reads from the ROM 151 a program corresponding to the selected DSP mode (“HALL”, “JAZZ”, “ROCK”, or “DISCO” mode) and conducts DSP for the digital audio signal stored in the DSP RAM. The amplifier section AM amplifies the analog audio signal resultant from the DSP and then outputs the amplified signal to the speaker terminal Ts. The speaker connected to the terminal Ts produces sound.
The display section 153 displays information of the selected sound source (e.g., a CD player), the selected DSP mode (e.g., “JAZZ”), and the like.
To obtain an acoustic effect corresponding to each DSP mode, a parameter value for each DSP mode is determined for the DSP parameter by the maker or manufacture of the system.
There has also been known an amplifier system having a function for the user to set various DSP parameters to be memorized therein.
However, the user must have technical knowledge to control DSP parameters in the amplifier system of the prior art. That is, a user not familiar with acoustics cannot recognize or perceive by senses what kind of effect is attained by controlling which one of the DSP parameters.